Needy demands usually are a bother. Try doing some things in her interests for a change.
I don't know if it helps, but I can relate. My mom and I had an OK relationship, but she had health issues and if I showed that I was having problems it upset her and made her sicker. So I learned to keep everything bottled up inside so I wouldn't hurt her. I didn't have any friends to talk to. The kids at school were a big source of my unhappiness. I would probably have killed myself but I knew that would also hurt my mom, so I was trapped here. I'm sorry, this probably doesn't help any. I wish I could say things were better for me now, but they aren't. I hope you can find a way out of your sadness and find someone to talk to who can actually help you. It makes me sad to think of other people suffering like this too.